What are some really good resources for gray rocking?

I have, to put it lightly, emotional issues. I've battled with myself back and forth for a year now if I'm the narcissist or not or if I'm the problem. I started therapy before I dumped him and so I'm learning the truth now. I've found out a couple things since I dumped him that involve STIs so of course, as any decent human being would, I messaged him to warn him about this and to go to a doctor. Not for him but mostly to keep my ass out of trouble in case things happen in the future and he wants to put the blame on me (like always). That of course turned into another nonsensical conversation because he makes me feel like I'm in another fucking dimension than him when I try to explain and rationalize things to him.

I am such an emotional person. All of my emotions are on full volume all the time and I need medication for it as well as therapy. I'm just learning about this gray rock thing and I realize that's been my problem this whole time. I am so reactive to everything he says and I can't stop finding myself trying to explain things to him in a way that he would understand. I've even found myself getting so angry and frustrated to the point of name calling and saying very hurtful things which I really wish I didn't because I don't want to make it a habit and well obviously I feel bad even though my therapist says I shouldn't (with him).

What are some good resources for gray rocking? Is there anything about gray rocking that can coincide with DBT and therapy for BPD? I've been a victim of many things but I find I just make things worse by not being able to control myself. I don't want to be like that towards people, even if they're hurting me first.